This study will trace the ontogeny of communication from the earliest appearance of action patterns that will later become part of functionally specific communicative skills. Unlike previous research that has looked primarily at such "proto-communicative" actions as part of a general communicative function from their first appearance, this research intends to show how components of intentional communicative acts often develop independently as part of functional systems that are not, in early infancy, related to communication. The primary hypothesis of this investigation is that communicative behavior must be understood as an evolving system of actions that, through the parent-infant interaction, become recruited from other functional systems and re-organized to serve increasingly specific communicative functions for the individual. Twenty mother-infant pairs will be observed weekly for the first year, bi-weekly in the second year during spontaneous interaction in the laboratory and at home. Behavior is coded using a continuous time base. Quantitative methods will be used to isolate systematically occurring sequences from those that occur by chance, both within an observation session, and over time developmentally. Qualitative methods, based on a computer-assisted interactive dialogue between the researcher and the video recording of the parent-infant system under investigation, will also be used.